 Wysłany: Wto 18:41, 08 Lut 2011 Temat postu: tory burch shoes Separation of precolumn derivatiz |
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| Separation of precolumn derivatization of 3 - hydroxybutyrate optical isomers
thyl3-hydroxybutyrateandcolumntemperatureonseparationofopticalisomersofderivativeofethyl3-hydroxybutyratewereinvestigated. Thethermodynamicparametersintheprocessofsepa-rationofopticalisomersweredeterminedinordertodiscussdrivenpowerintheprocessofseparationofopticalisomers. Theexperimentresultsshowedthatquantitativetransformationfromethyl3-hydroxybutyrateintoethyl3 a (2,2,2-trifluoroacetoxy) butyratecanbeobtainedunderthefollowingoptimalreactionconditions: molarratiooftrifluoroaceticanhydridetoethyl3-hydroxybutyrate5: 1, reactiontime5minatroomtemperature. Undertheeolumntemperature62oC, theseparationfactorandseparationdegreeofopticalisomersofethyl3 a (2,2,2-trifluoroacetoxy) butyratewere1.02and1.26, respectively. Itwasdemonstratedthatseparationofopticalisomersofethyl3 a (2,2,2 a trifluoroacetoxy) butyratewasenthalpy-drivenprocessandtheinteractionbetweensurfaces0f a cyclodextrinandethyl3 a (2,2,2-trifluoroacetoxy) butyratemightmainlycontributetotheseparation. KeywordsEthyl3-hydroxybutyrate, ethyl3 a (2,tory burch shoes,2,2-trifluoroacetoxy) butyrate, opticalisomers, chiralsepa-ration, derivatization (Received10August2006: accepted5December2006 )::::::::::::::::::::: :::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::::::technology. The book systematically describes the overview of near infrared spectroscopy, near infrared absorption spectra of the basic principles of near infrared spectroscopy instruments, commonly used chemometrics methods and software, qualitative and quantitative analysis, on-line process analysis techniques, and focuses on the technology the latest developments and applications in the petrochemical field. The book available in analytical chemistry, instrumental analysis, process optimization, chemical and petrochemical production, and agriculture,uggs online, food, textile, pharmaceutical and environmental science and technology workers and other professional colleges on student reading and reference. Wish to purchase,tory burch sale, please contact the Press (Ding Men Wai Avenue, Dongcheng District, Beijing, No. 58, Post Code: 100011; Tel :010 -84,289,tory burch outlet,974). More articles related to topics： discount cosmetics mac Choice of fruit and vegetab Tory Burch Shoes Dad cooking _4155 uggs online Thermo Fisher Scientific expanded GC |
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